Moto Guzzi Le Mans III
With Ian Falloon
By the beginning of the 1980s the Japanese motorcycle manufacturers finally understood the balance between power and chassis, unleashing a wave of powerful motorcycles that handled well.
This left the European manufacturers in a quandary. Without their traditional handling advantage; where next with their ageing designs? Moto Guzzi was in a similar position to Ducati and Laverda.
The Moto Guzzi Le Mans had been one of the standout sporting motorcycles of the mid 1970s but by the end of the decade the high compression twin was struggling to meet tougher noise and emission controls. While the Le Mans evolved into the similar Mark II in 1978, by 1980 these big-valve twins breathing through open bell mouth Dell’Orto carburettors couldn’t be sold in most markets.
As sporting motorcycles were still important for Moto Guzzi at that time, Moto Guzzi boss De Tomaso sanctioned the development of an evolutionary Le Mans; the 850 Le Mans III. When it was released it appeared to be a simple restyle, but with 44 official updates from the Le Mans II it was effectively a new motorcycle.
Setting the Le Mans III apart were new angular cylinders and heads, but the capacity remained at 844 cc, with 44 and 37 mm valves. The pushrod and rocker valve actuation set-up was unchanged so valve adjustment remained an easy task.
A thicker cylinder head gasket lowered the compression ratio slightly, to 9.8:1, and the Dell’Orto PHF 36 mm carburettors were new. As the days of open bell mouth carburettors were numbered, to maintain existing performance levels the large capacity air-cooled twin needed a more efficient intake and exhaust system.
Guzzi’s engineers, headed by the legendary Umberto Todero, managed to create an airbox and exhaust system that was quieter than the Le Mans and Le Mans II, but produced more power.
A heavier crankshaft smoothed out low speed running but the single plate dry clutch, five-speed transmission and shaft final drive were unchanged. The factory claimed the Le Mans III’s power was increased by three horsepower over the Le Mans II but didn’t actually provide a figure.
When it came to the chassis it was very much business as usual with the Le Mans III. Moto Guzzi resisted the trend towards smaller wheels, fat tyres, anti-dive braking, and single shock rear suspension. A longer swingarm stretched out the wheelbase to 1505 mm, improving high-speed stability and providing more room for a passenger.
But the narrow swingarm still only allowed a small 110/90-section rear tyre. This wasn’t really a functional problem as wider tyres were more fashionable than necessary on the moderately powered sporting Guzzis. Moto Guzzi did follow fashion by including air assistance for the front fork and twin Paioli shocks. The 18-inch cast FPS wheels were as before, as were the integrated Brembo disc brakes.
The Le Mans III was as much about style as performance. From the reshaped 25-litre fuel tank, smaller wind tunnel designed fairing, and new seat; it was probably the dominant 100 mm white-faced Veglia tachometer that did as much to sell the Le Mans III as anything else. Despite the impressive cockpit, in many respects the Le Mans III was still a relic of the 1970s.
In 1981 there were few motorcycles with battery and points ignition and a skinny 35 mm front fork. But when it came to style and useable all round performance the Le Mans III was very much at the forefront. The claimed weight was a reasonable 206 kg, and it was an attractive machine.
While retaining the compact dimensions of its predecessor the Le Mans III provided performance comparable to other 850 and 900 cc twin cylinder motorcycles. The Le Mans III was the perfect machine for riders who appreciated the virtues and simplicity of older motorcycles but required modern levels of performance and civility.
Five Facts about the Moto Guzzi Le Mans III
- The V35 Imola and V50 Monza of 1979 had a new angular fairing and tailpiece designed by de Tomaso’s automotive division at Modena and this influenced the Le Mans III.
- A racing uprating was also available. This included a B10 camshaft, Dell’Orto PHM 40 B carburettors and manifolds, racing exhaust system and a straight cut close ratio gearbox.
- Le Mans III production began at the end of 1980 and continued until 1985. With over 10,000 produced the Le Mans III was the most successful of all the sporting Moto Guzzis.
- The release of the 850 Le Mans III provided a new basis for an endurance racer and at the 1982 Endurance race at Imola, Francesco Giumbini, Alfio Micheli, and Francesco Tamburini finished fourth, with the German entry of Mattias Meyer and Klaus Hoffman eighth. This was followed by fifth and ninth respectively at the Liege 24 Hour race. Renato Pasini in Italy and Wolfgang Speyer in Germany continued to race the Le Mans III until 1985.
- The release of the Le Mans III provided the impetus for Pennsylvania dentist Dr. John Wittner to return to racing. Wittner had earlier been a racer and service manager at a Moto Guzzi dealership before training as a dentist. For the 1984 AMA endurance racing series the 850 Le Mans qualified to compete against 750 cc fours. Greg Smrz won the title, prompting Wittner to sell his dental practice and go racing full time.
